Are you trying to trigger the EL-5 via wireless communication from the XC3 on your camera? I don't see that described anywhere.
If you want to turn your EL5 into a wireless flash, you need a Godox trigger and a Godox receiver, both for Canon.
Here, 'Compatible with Canon' means simply that the trigger/receiver combo transmits the Canon specific flash control signals that would normally run through the hotshoe. It does not mean that the Godox trigger can drive a Canon flash via wireless signals. (Similar to autofocus on RF mount, Canon would have a very strong Opinion about such a function offered by a third party manufacturer.)